position is estimated from Argo track in Area 1; depth estimated from GeoMapApp; 1987 cruise, http://cmgds.marine.usgs.gov/fan_info.php?fa=1987-033-FA, accessed 5 June 2015: "The findings of this cruise suggest that hydrothermal activity has taken place on Mohns Ridge. The presence of temperature anomalies, sediment elutriation structures in rippled, bioturbated sediment, and a water-column density plume suggest that Area 1 was hydrothermally active at the time of this investigation."; Schwab et al. (1988): "Area 1 is located within the median valley of Mohn's Ridge between longitudes 1 05'W and 0 05'E."; R/V G.O. Sars in June/July 2013, http://www.uib.no/en/geobio/57318/research-overview, accessed 5 June 2015: "By using a CTD equipped with state-of-the-art sensors for Eh, CO2 and CH4 as well as onboard gas chromatography for H2 and CH4, hydrothermal anomalies were found in the water column above the Mohns Ridge. These point to at least three more vent systems along this section of the AMOR"

Year and How Discovered (if active, visual confirmation is listed first):